A COMPARISON OF OPTICAL LIGHT TRANSMISSION AND DYNAMIC VISCOELASTIC PROPERTIES FOR DETERMINING TRANSITIONS IN THERMOTROPIC LIQUID-CRYSTALLINE POLYMERS

Optical light transmission and dynamic viscoelastic properties are compared over the range of flow temperatures for two homogeneous thermotropic liquid crystalline polymers, TLCP, of identical structure but of different molecular weight. In the previous work involving only the higher molecular weight polymer, a Rheometerics Mechanical Spectrometer was used to study the dynamic viscoelastic properties, and this method proved to be a useful means for characterizing the isotropization process for this type of polymer. Inthe current work, parallel polarized light transmission wasstudied as another useful means of following the transitio processes in homogeneous TLCP’s. The light transmission data so obtained are compared with the light transmission data using crossed polarizers reported by previous workers for LCPs. Also included in this study was the characterzation of the LC transitions by DSC and polarized light microscopy. © 1990, The Society of Polymer Science, Japan. All rights reserved.